Aimed at the problem that the effect of positioning such as the positioning accuracy, positioning impact and shock is difficult to predict during the designing process of the actual switch electromagnetic valve positioning system, an actual positioning system control model was established based on AMESim. The simulation analysis of it was carried out. The research shows that the load speed and quality of positioning system, positioning control switch and relay switch time belong to hard parameters of positioning system, which can be better predicted and compensated. The switch response time of the switch electromagnetic valve and oil compressibility, which belong to the soft parameters of positioning system, are the main factors affecting positioning system dynamic process, which variable range is affected by many factors, and not easy to control. For the positioning system，in which the load quality is 5 000 kg, movement speed is 0.2 m/s, load positioning journey is 1 200 mm and oil modulus is 1 700 MPa，when other factors are constant and the response time of the switch electromagnetic valve is changed from 10 ms to 100 ms, the position error is raised from 11.8 mm to 19.8 mm, and positioning impact is increased from 2.8 mm to 4 mm.